title: Analysis of radiation-induced cell death in head and neck squamous cell carcinoma and rat liver maintained in microfluidic devices.
abstract: OBJECTIVE
  The aim of this study was to investigate how head and neck squamous cell carcinoma (HNSCC) tissue biopsies maintained in a pseudo in vivo environment within a bespoke microfluidic device respond to radiation treatment.
  
  
  METHODS
  Feasibility study.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  Thirty-five patients with HNSCC were recruited, and liver tissue from 5 Wistar rats was obtained. A microfluidic device was used to maintain the tissue biopsy samples in a viable state. Rat liver was used to optimize the methodology. HNSCC was obtained from patients with T1-T3 laryngeal or oropharyngeal SCC; N1-N2 metastatic cervical lymph nodes were also obtained. Irradiation consisted of single doses of between 2 Gy and 40 Gy and a fractionated course of 5×2 Gy. Cell death was assessed in the tissue effluent using the soluble markers lactate dehydrogenase (LDH) and cytochrome c and in the tissue by immunohistochemical detection of cleaved cytokeratin18 (M30 antibody).
  
  
  RESULTS
  A significant surge in LDH release was demonstrated in the rat liver after a single dose of 20 Gy; in HNSCC, it was seen after 40 Gy compared with the control. There was no significant difference in cytochrome c release after 5 Gy or 10 Gy. M30 demonstrated a dose-dependent increase in apoptotic index for a given increase in single-dose radiotherapy. There was a significant increase in apoptotic index between 1×2 Gy and 5×2 Gy.
  
  
  CONCLUSIONS
  M30 is a superior method compared with soluble markers in detecting low-dose radiation-induced cell death. This microfluidic technique can be used to assess radiation-induced cell death in HNSCC and therefore has the potential to be used to predict radiation response.
authors.affiliation: Hull York Medical School, Hull, United Kingdom.
authors.forename: Simon D
authors.initials: SD
authors.lastname: Carr
authors.forename: Victoria L
authors.initials: VL
authors.lastname: Green
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Stafford
authors.forename: John
authors.initials: J
authors.lastname: Greenman
mesh_terms: D000818:Animals; D017209:Apoptosis; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000532:radiotherapy*; D016923:Cell Death / Q000528:radiation effects*; D045304:Cytochromes c / Q000032:analysis; D005240:Feasibility Studies; D006258:Head and Neck Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D006801:Humans; D007150:Immunohistochemistry; D053538:Keratin-18 / Q000032:analysis; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D007822:Laryngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy; D008099:Liver / Q000473:pathology; D046210:Microfluidic Analytical Techniques; D009959:Oropharyngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy; D011879:Radiotherapy Dosage; D051381:Rats; D017208:Rats, Wistar
chemical_list: D053538:Keratin-18; D045304:Cytochromes c; D007770:L-Lactate Dehydrogenase
keywords: head and neck squamous cell carcinoma; microfluidic techniques; radiotherapy; rat liver